Polly Hoppin, ScD, Research Professor, University of Massachusetts Lowell
Philip R.S. Johnson, PhD, Environment and Health Senior Program Director, The Heinz Endowments
Cancer remains a devastating health crisis nearly fifty years after the declaration of the “War on Cancer.” Better treatments and earlier detection have dramatically improved prognosis for some types of cancer, yet significant disparities persist (National Cancer Institute 2022). Cancer survivors often confront long-term health challenges (Oeffinger et al. 2006). Nationally troublesome trends exist, including rising rates of cancer in young people (Miller et al. 2020; di Martino et al. 2022), increases in lung cancers among never-smokers (Pelosof et al. 2017), and growing rates of testicular and kidney cancer, as well as most kinds of leukemia (National Cancer Institute 2022). It appears our medical system’s dominant approach to addressing cancer through treatment and screening is not fully working, which begs the question: what stones have been left unturned in cancer prevention?
One important strategy for preventing new cases of cancer is reducing exposure to tobacco smoke (Moolgavkar et al 2012). Ongoing investment is needed to continue that progress; however, a recent study suggests that factors other than smoking are also contributing to cancer incidence. For the 12 types of cancer for which smoking is a known risk factor, the study concluded that eliminating smoking entirely would reduce the incidence of these 12 cancer types by about 40 percent on average in U.S. counties, thus leaving 60 percent of cancer cases still occurring. More important, the benefit of eliminating smoking would vary substantially from county to county across the U.S. (Myers et al 2020). While this finding affirms the importance of smoking cessation, it also underscores the need to understand what other factors could be contributing to cancer risk and what more can be done to address them.
We are exploring these questions in Southwestern Pennsylvania. In Allegheny County, home to Pittsburgh, a follow up analysis estimated that lung cancer would drop only 10.6 percent if smoking were eliminated, compared to an average reduction in lung cancer rates across all U.S. counties of 62.5 percent (Myers et al. 2021). It turns out that Allegheny County is in the top four percent of U.S. counties for estimated risk of cancer from diesel and air pollutants categorized as “air toxics,” with environmental justice areas at even higher risk, illuminating long-standing inequities in exposures. Cancer risk from large industrial pollution sources, such as iron and steel production including coking, is even more striking (Graham 2021). In addition, Pennsylvania’s average levels of radon are the third highest compared to other states (World Population Review 2022). Over the past 15 years, the region has seen intense development by the oil and gas industry with activities near homes, schools, and water supplies raising concerns about carcinogenic exposures (Environmental Health News 2021; Warner et al. 2013.) Additional environmental cancer risks in the area include asbestos, pesticides, carcinogenic by-products of water treatment, and per-and polyfluoroalkyl substances—a class of thousands of chemicals known as PFAS (Pennsylvania DEP 2021; Cadwallader et al. 2019).
Elevated exposures to toxic chemicals in Southwestern Pennsylvania, along with elevated rates of environmentally sensitive cancers, points to an opportunity for cancer prevention in the region (Jacobs 2021). A 2019 symposium in Pittsburgh reviewed the relevant science and discussed ways forward: Who needs to be at the table in debates about how to catalyze change? What mix of activities could shift dynamics that have impeded progress towards healthy environments over many years? The symposium launched the Cancer and Environment Network of Southwestern Pennsylvania (CENSWPA) now a thriving gathering place for collaboration among a wide range of organizations. Participants can engage via a monthly email digest of science, news and resources; quarterly full network meetings; and project-focused workgroups. Highlights of the past year include:
- Data analyses and research syntheses on environmental exposures and cancer incidence.
- A speakers’ series for people impacted by cancer.
- Community-level trainings.
- Piloting a transition from the use of toxic chemicals to safer alternatives in a community space where people gather for cancer support.
- Establishing a framework for prioritizing actions with and across sectors towards “an equitable future where no individual in our region is diagnosed with cancer due to exposures in the environments where they live, work, play and go to school.”
Within a multi-sector approach to reducing environmental chemicals in the context of cancer prevention, health professionals and cancer-focused groups have an important role. Engaging them is a priority of CENSWPA and an allied national initiative, the Cancer Free Economy Network (CFEN). Several recent activities are promising, including partnerships to convene major cancer and environment forums with influential organizations such as the American Association of Cancer Research, the National Association of Chronic Disease Directors along with the Centers for Disease Control and Prevention, and the Dana Farber Cancer Institute/Harvard Cancer Center. The Childhood Cancer Prevention Initiative is a cross-sector collaboration among childhood cancer-focused groups, scientists, policy advocates, and businesses to advance research and drive demand for safer products and manufacturing processes. A Joint Statement on Cancer Prevention by organizations ranging from the National Medical Association to the American Public Health Association to Latinas Contra Cancer makes the case for elevating attention to these issues and establishes a framework for accountability. These activities complement the work of organizations like Less Cancer, responsible for establishing an annual Cancer Prevention Day, which have long track records in calling for reducing environmental chemicals as an important element of primary prevention.
Through these activities, health professionals and health advocacy groups are learning how they can elevate environmental chemicals as an important element of cancer prevention, including in research design, clinical practice, policy advocacy, and in cancer initiatives such as the Beau Biden Moonshot and states’ 5-year cancer prevention and control plans. Ongoing participation in the networks gives health leaders the opportunity to examine barriers to cancer prevention, including those they may contribute to, and to gain confidence in their ability—and responsibility—to use their power as trusted messengers to call for dramatic reductions in carcinogens. The networks also help leverage resources for doing so, not only within but beyond the health sector. We are excited about progress so far and the promise ahead of this approach to expand the scope and impact of cancer prevention.
Acknowledgements
The authors wish to acknowledge CENSWPA and CFEN colleagues as well as the Ceres Trust, Fine Foundation, Garfield Foundation, Passport Foundation, and Roy A. Hunt Foundation, in addition to the Heinz Endowments, for financial support of network activities.
References
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